Unfortunately, the appearance of the Cryptomeria - its off-color and browning - suggests that they are beyond recovery at this point. We do not see evidence of an infection or a pest outbreak. (Scale insects are minute and while some species can feed on Cryptomeria needles, they would not be causing this widespread damage unless the plant was heavily populated. In that event, treatment would be impractical and plant replacement would be needed anyway.)

As to what caused their stress and damage, it's hard to determine with certainty since symptoms in evergreens can take months to manifest fully. A likely factor, though, is abiotic - meaning that neither a pest nor disease was responsible, and environmental conditions instead are the culprit. Very few trees and shrubs succumb during their first couple of years in the ground due to a pest infestation or disease outbreak unless either was already well-entrenched in the plant to begin with. (This is not the case here or the plants would have already looked weakened and ailing at the time of planting.) While we do not have a lab accepting samples from the general public, this has been the experience of our plant pathologists and entomologists.

Root moisture is the most common cause of failure for landscape plants. This can take the form of accidental over- or under-watering (and sometimes both, one after the other as we unintentionally over-compensate or as weather patterns shift dramatically). Differentiating between the two is difficult because their symptoms overlap considerably and, as mentioned above, can take weeks after the initial event to manifest. If the soil drains well in this location, perhaps they roots got too dry on one or more occasions. Planting evergreens in late fall can be riskier than earlier in the season since they require more consistent access to unfrozen water as they establish new roots during winter. (Evergreens also lose water faster than deciduous plants during winter and, if frozen soil or lack of precipitation/irrigation prevents them from replacing it, the foliage will discolor and desiccate.)

"Failure to establish" is the general diagnostic term used when plants don't develop a good root system in their first year or two after planting. Top growth and root growth simulate each other hormonally in healthy plants. Since weakened top growth, slowly starving from lack of root support, cannot stimulate enough replacement root growth, this feedback loop leads to slow plant decline. Evergreens usually discolor instead of actively shedding foliage when this happens, and this appears to be the situation in the photos.

Fortunately, if you wish to try again, Cryptomeria should do well in this location based on what we can see from the images - good sun exposure, room to mature - and from your description, good drainage. Perhaps planting in spring instead will result in more success; alternatively, you can try late summer or early autumn (Aug-Sept) instead of late fall (Oct-Nov). It's also possible the plants had compromised root systems prior to planting, but we cannot determine that after this much time has passed since root decline in the interim could have resulted from an array of causes. When feasible, install young plants instead of older plants, as they acclimate much more easily and establish faster with less stress on the plant. In all cases, make sure roots are well-disentangled prior to planting, and ensure the root flare (where roots start branching off of the trunk) sits just level with the soil surface so the root ball isn't buried too deeply.

If you do not wish to give up on these plants yet, all you can do for now is to monitor the soil moisture for watering needs as we move through winter. Cold temperatures will certainly slow the pace of water loss, but if we have recurring mild spells and limited (or too sporadic) precipitation, they may benefit from occasional watering. Feel the soil as best you can around five inches deep (excluding any mulch); if still moist, watering shouldn't be needed; if fairly dry, soak the root zones well. If using outdoor hoses aren't an option, you can use several watering can-fulls from inside faucets; just make sure the water is tepid but not too warm. Do not fertilize, nor would they benefit from any sort of pesticide (insecticide, fungicide, etc.) application.

"Bronzing" (this orange-brown blush to the foliage) is a normal feature of some Cryptomeria varieties in winter, so if they are recovering well, they should re-green completely in spring. Rarely is bronzing this extensive, though, on cultivars of this type. As needled evergreens mature, the browning, dying, and shedding of its inner-most needles is normal. On Cryptomeria, sometimes entire branch-lets die back during this process; they can be clipped off if an eyesore, otherwise they will fall off on their own in time. In your case, this is likely happening as a combination of normal maturation coupled with whatever is stressing the entire plant.

Miri